The present invention relates generally to collapsible wheelchairs and wheelchair frame assemblies that may be deployed in alternative configurations. More particularly, the present invention relates to wheelchairs that can be narrowed by the user for passage through restricted areas, or foldably retracted into a convenient stowage disposition.
Conventional wheelchairs can be vexatiously difficult to maneuver, particularly where small, confined areas must be traversed. Business persons confined to wheelchairs who must frequently travel are faced with a variety of obstacles The complications presented by stairs, escalators and metal detectors are only part of the problem Ordinary difficulties encountered by wheelchair users when traveling through crowded airports can be overshadowed by the problems in boarding the aircraft The narrow aisles of commercial aircraft are a significant impediment to the traveling wheelchair user. Such individuals usually must check their personal wheelchair as baggage, thus limiting personal autonomy and comfort. The physical assistance of airline personnel or others is subsequently required
Most airlines attempt to accommodate wheelchair-confined passengers by temporarily substituting lightweight, low, profile wheelchairs of reduced dimensions. Such chairs facilitate unobstructed clearance and passage through the narrow aisles. Exemplary of such "temporary" airline wheelchairs are those chairs depicted in U.S. Pat. No. 4,639,012 and 4,678,202 issued to Jenson on Jan. 27, 1987 and Jul. 7, 1987, respectively. In my opinion such prior art wheelchairs are designed strictly for short-term use, and besides aggravating the user, they provide minimal comfort. All such prior art wheelchairs known to me are ineffective for long-term, everyday use.
One major disadvantage associated with temporary airline wheelchairs is that the handicapped passenger has no opportunity to move about independently in the plane after he is seated. After seating, the chair is stowed out of reach. Moreover, considerable inconvenience and delay are experienced after landing, since the handicapped passenger must wait to be transported by the airline staff to the terminal. Once the destination is reached, the handicapped user must switch back to his everyday wheelchair. First, however, he must endure the inevitable delays associated with retrieval of his chair.
Many find this loss of independence extremely inconvenient and uncomfortable. Hence it is desired to provide a full-size wheelchair which can be quickly disassembled and carried with the, passenger for storage on board the aircraft. Additionally, it is desired to provide such a wheelchair which may be selectively configured at will to enable the individual to move about independently in space-restricted areas such as airline aisles and the like.
Known conventional wheelchairs are also inconvenient for use in the typical business office. Efficient access to office desks, file cabinets, computer tables, and book shelves is generally compromised for the wheelchair-using business person. Elevated service counters in restaurants, stores, and banks are also typically out of reach of the individual seated in a wheelchair. Similarly, it is difficult for those in wheelchairs to comfortably approach conventional lecterns or podiums found in courtrooms or other public places. It is also extremely difficult for such individuals to comfortably mount popular vehicles such as jeeps, vans, and pick-up trucks
Thus the wheelchaired individual experiences inconvenience, loss of independence, discomfort, and delay in conducting routine business transactions. But to make matters worse, conventional wheelchairs also hinder the handicapped individual in the performance of countless routine household tasks. For example, elevated kitchen cabinets, closet and refrigerator shelves, and other storage facilities are generally out of reach. Hence it is desired to provide a wheelchair which may be conveniently user-adjusted and/or configured to enable access to all types of areas encountered in various business and household settings.
A further disadvantage associated with known prior art wheelchairs is that the large wheels are permanently positioned on the rear of the frame. The user must remain in the same awkward position, with the torso extended forward and the arms reaching backward to propel the chair. After extended periods of use the individual's arms, back, and shoulders can tire and become strained. Additionally, it is often quite difficult to maneuver the chair comfortably with the drive wheels in the rear. Hence it is desired to provide a wheelchair which may be readily reversibly oriented at the user's option so that the large drive wheels are in front for comfort and enhanced maneuverability.
Over the years, various improvements have been introduced to overcome difficulties experienced in maneuvering wheelchairs. For example, a wide variety of folding wheelchairs have been proposed in the prior art which facilitate convenient storage for travel. Foldable wheelchairs are disclosed in the following U.S. Pat. Nos. 4,025,088, issued May 24, 1977 to Rothschild; U.S. Pat. No. 4,326,732, issued to Gall Apr. 27, 1982; Dion U.S. Pat. No. 4,371,183 issued Feb. 1, 1983; U.S. Pat. No. 4,542,918 issued to Singleton on Sep. 24, 1985; U.S. Pat. No. 4,577,878 issued to Roy Mar. 25, 1986; U.S. Pat. No. 4,607,860 issued Aug. 26, 1986 to Vogel; U.S. Pat. No. 4,684,171 issued Aug. 4, 1987 to Roy, U.S. Pat. No. 4,736,960 issued to Batty, Apr. 12, 1988; and Design U.S. Pat. No. D277,949, issued Mar. 12, 1985 to Minnebraker. Nassiri, U.S. Pat. No. 4,592,570 issued Jun. 3, 1986 comprises means for adjustment of seat orientation and convenient quick-release wheels to facilitate folding.
Other improvements are directed to enhanced wheelchair comfort. Rodaway, U.S. Pat. No. 3,881,773 issued May 6, 1975 employs a reclining back; Rodaway U.S. Pat. No. 3,990,745, issued Nov. 9, 1976 teaches the use of a removable back to facilitate convenient transfer from the wheelchair to a bed or other support. Presty U.S. Pat. No. 3,584,890 issued Jun. 15, 1971 comprises an arm rest assembly which may be removed and used as a walker to assist the wheelchair patient in rising from the chair.
Minnebraker U.S. Pat. Nos. 4,351,540 (Sep. 28, 1982); U.S. Pat. No. 4,515,383 (May 7, 1985); U.S. Pat. No. 4,477,098 (Oct. 16, 1984); U.S. Pat. No. D269,172 (May 31, 1983); and U.S. Pat. No. D271,679 (Dec. 6, 1983) disclose wheelchairs which can be readily adapted for use by individuals of different sizes and physical capabilities. The Minnebraker designs are also ideally suited for participation in wheelchair sports activities. Other wheelchairs specifically directed to use for sporting activities are proposed by Sanaski, U.S. Pat. No. 4,166,631, issued Sep. 4, 1979; and Farnam, U.S. Pat. No. 4,545,593 issued Oct. 8, 1985. The seat of the last-mentioned Farnam chair may be selectively adjusted for comfortable height and tilt.
Various others have directed their attention to providing width-adjustable chairs specifically for navigating narrow passageways. Haury, U.S. Pat. No. 4,082,348 issued Apr. 4, 1978 comprises adjustable transverse frame members cooperative with flexible seat members to facilitate width adjustment U.S. Pat. No. 4,730,842 issued Mar. 15, 1988 to Summers teaches the use or split clamps for facilitating horizontal adjustments to the seat. Pivotal foot plates facilitate convenient passage through narrow areas. The reduced-width wheelchair disclosed by Rodaway in U.S Pat. No. 4,164,354 issued Aug. 14, 1979 comprises a scissor-type foldable frame which mounts the front and rear wheels in parallel alignment. Volin U.S. Pat. No. 4,648,615 issued Mar. 10, 1987 comprises rotatable arm supports which may be pulled inward to narrow the wheelchair frame for enabling passage in space-restricted areas.
One prior art patent of particular relevance to my invention is Ferguson U.S. Pat. No. 4,098,521 issued Jul. 4, 1978. When the large rear wheels of the Ferguson chair are removed, the chair may be tilted to engage secondary wheels mounted in alignment with the narrow interior frame. The arm and foot rests may be conveniently pivoted away or removed to substantially reduce the overall width. While the chair is highly maneuverable, it presents certain disadvantages. For example, the Ferguson chair comprises a rather cumbersome framework with secondary drive linkage and foot pedal adjustments Moreover, there are no convenient means suggested for effectuating seat width or height adjustments. Use of hand-operated levers associated with either side of the chair is also rather disadvantageous. Finally, some difficulty is encountered in manipulating the rear wheel release mechanism.
Finally, in the prior art known to me, various systems are proposed for facilitating quick-release of the chair rear wheels for storage or conversion to a narrower frame. Patents of some relevance to my invention are U.S. Pat. No. 3,847,440 issued Nov. 12, 1974 to Mattson; Anderson, U.S. Pat. No. 4,392,690, issued Jul. 12, 1983; U.S. Pat. No. 4,474,385 issued to Costello on Oct. 2, 1984; and, Costello U.S. Pat. No. 4,582,448 issued Apr. 15, 1986; U.S. Pat. No. 4,679,862 issued Jul. 14, 1987 to Luo.
The chair described in my above-referenced co-pending patent application greatly improves an individual's ability to adapt to a variety of situations. However, sometimes the collapsing, foldable frame sections may bind somewhat where the user fails to maintain alignment. The instant chair frame construction solves frame alignment problems, makes it easier to collapse or unfold and deploy the frame, more readily facilitates stowage, and improves the individual's ability to adapt the chair for a variety of situations. Additionally, this improved version allows the seat back to lock more securely to the seat base after assembly or disassembly.